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1.
Plant Physiol Biochem ; 148: 63-69, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31945668

RESUMO

Proper storage prolongs peony market supply. Here, we determined the changes in fresh weight and expression of four aquaporin genes under dry storage (DS) and wet storage (WS). It has showed that after harvesting, the fresh weight change was accompanied with flower opening. After both short- and long-term of storage, the water uptake efficiency in DS group was greater during the first few vase days, providing a direct material basis of DS improved vase quality. The gene expression results showed that PlPIP1;3 and PlTIP2;1 were mainly expressed in petals, whereas PlNIP1;2-like and PlSIP2;1 were mainly expressed in the green tissues. In addition, the expression of PlTIP2;1 in the petals was consistent with the flower opening process, indicating that it may play a major role in facilitating water uptake. During cold storage, the expression of PlPIP1;3 and PlTIP2;1 was higher or more rapidly induced in the DS group, and thus we deduced that they play important roles in improving the vase quality of DS. Furthermore, the expression of PlNIP1;2-like in the early stage of the DS group was more stable than in WS, which may also be partially responsible for the vase quality improvement. In contrast, PlSIP2;1 may not be involved, since no significant change was observed between the DS and WS group. In short, the expression of PlPIP1;3 and PlTIP2;1 in the DS group during storage may improve water uptake efficiency during the vase period and then improving the vase quality of cut peony.


Assuntos
Agricultura/métodos , Aquaporinas , Flores , Paeonia , Água , Aquaporinas/genética , Aquaporinas/metabolismo , Transporte Biológico , Regulação da Expressão Gênica de Plantas , Paeonia/metabolismo , Água/metabolismo
2.
Proc Natl Acad Sci U S A ; 117(3): 1779-1787, 2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31907321

RESUMO

Insects are highly successful, in part through an excellent ability to osmoregulate. The renal (Malpighian) tubules can secrete fluid faster on a per-cell basis than any other epithelium, but the route for these remarkable water fluxes has not been established. In Drosophila melanogaster, we show that 4 genes of the major intrinsic protein family are expressed at a very high level in the fly renal tissue: the aquaporins (AQPs) Drip and Prip and the aquaglyceroporins Eglp2 and Eglp4 As predicted from their structure, and by their transport function by expressing these proteins in Xenopus oocytes, Drip, Prip, and Eglp2 show significant and specific water permeability, whereas Eglp2 and Eglp4 show very high permeability to glycerol and urea. Knockdowns of any of these genes result in impaired hormone-induced fluid secretion. The Drosophila tubule has 2 main secretory cell types: active cation-transporting principal cells, wherein the aquaglyceroporins localize to opposite plasma membranes, and small stellate cells, the site of the chloride shunt conductance, with these AQPs localizing to opposite plasma membranes. This suggests a model in which osmotically obliged water flows through the stellate cells. Consistent with this model, fluorescently labeled dextran, an in vivo marker of membrane water permeability, is trapped in the basal infoldings of the stellate cells after kinin diuretic peptide stimulation, confirming that these cells provide the major route for transepithelial water flux. The spatial segregation of these components of epithelial water transport may help to explain the unique success of the higher insects in regulating their internal environments.


Assuntos
Transporte Biológico/fisiologia , Drosophila melanogaster/fisiologia , Túbulos Renais/metabolismo , Água/metabolismo , Animais , Aquagliceroporinas/genética , Aquagliceroporinas/metabolismo , Aquaporinas/genética , Aquaporinas/metabolismo , Permeabilidade da Membrana Celular , Cloretos/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Feminino , Técnicas de Silenciamento de Genes , Túbulos Renais/citologia , Masculino , Túbulos de Malpighi/metabolismo , Modelos Animais , Oócitos/metabolismo , Osmorregulação , Xenopus
3.
J Plant Physiol ; 244: 153090, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31841952

RESUMO

The integral parts of the cell membranes are the functional proteins, which are crucial for cell life. Among them, proton-pumping ATPase and aquaporins appear to be of particular importance. There is some knowledge about the effect of the temperature during plant growth, including stress-inducing temperatures, on the accumulation of the membrane proteins: plasma membrane H+-ATPase and aquaporins, but not much is known about the effect of the phytohormones (i.e. brassinosteroids (BR)) on control of accumulation of these proteins. The aim of our study was to answer the question of how a BR deficit and disturbances in the BR perception/signalling affect the accumulation of plasma membrane H+-ATPase (PM H+-ATPase), the aquaporin HvPIP1 transcript and protein in barley growing at 20 °C and during its acclimation at 5 °C and 27 °C. For the studies, the BR-deficient mutant 522DK (derived from the wild-type Delisa), the BR-deficient mutant BW084 and the BR-signalling mutant BW312 and their wild-type Bowman were used. Generally, temperature of growth was significant factor influencing on the level of the accumulation of the H+-ATPase and HvPIP1 transcript and the PM H+-ATPase and HvPIP1 protein in barley leaves. The level of the accumulation of the HvPIP1 transcript decreased at 5 °C (compared to 20 °C), but was higher at 27 °C than at 20 °C in the analyzed cultivars. In both cultivars the protein HvPIP1 was accumulated in the highest amounts at 27 °C. On the other hand, the barley mutants with a BR deficiency or with BR signalling disturbances were characterised by an altered accumulation level of PM H+-ATPase, the aquaporin HvPIP1 transcript and protein (compared to the wild types), which may suggest the involvement of brassinosteroids in regulating PM H+-ATPase and aquaporin HvPIP1 at the transcriptional and translational levels.


Assuntos
Adenosina Trifosfatases/genética , Aquaporinas/genética , Hordeum/fisiologia , Proteínas de Plantas/genética , Aclimatação , Adenosina Trifosfatases/metabolismo , Aquaporinas/metabolismo , Brassinosteroides/metabolismo , Temperatura Baixa , Hordeum/genética , Temperatura Alta , Mutação , Proteínas de Plantas/metabolismo
4.
PLoS One ; 14(12): e0227020, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31887166

RESUMO

The heterogeneous distribution of soil salinity across the rhizosphere can moderate salt injury and improve sorghum growth. However, the essential molecular mechanisms used by sorghum to adapt to such environmental conditions remain uncharacterized. The present study evaluated physiological parameters such as the photosynthetic rate, antioxidative enzyme activities, leaf Na+ and K+ contents, and osmolyte contents and investigated gene expression patterns via RNA sequencing (RNA-seq) analysis under various conditions of nonuniformly distributed salt. Totals of 5691 and 2047 differentially expressed genes (DEGs) in the leaves and roots, respectively, were identified by RNA-seq under nonuniform (NaCl-free and 200 mmol·L-1 NaCl) and uniform (100 mmol·L-1 and 100 mmol·L-1 NaCl) salinity conditions. The expression of genes related to photosynthesis, Na+ compartmentalization, phytohormone metabolism, antioxidative enzymes, and transcription factors (TFs) was enhanced in leaves under nonuniform salinity stress compared with uniform salinity stress. Similarly, the expression of the majority of aquaporins and essential mineral transporters was upregulated in the NaCl-free root side in the nonuniform salinity treatment, whereas abscisic acid (ABA)-related and salt stress-responsive TF transcripts were more abundant in the high-saline root side in the nonuniform salinity treatment. In contrast, the expression of the DEGs identified in the nonuniform salinity treatment remained virtually unaffected and was even downregulated in the uniform salinity treatment. The transcriptome findings might be supportive of the increased photosynthetic rate, reduced Na+ levels, increased antioxidative capability in the leaves and, consequently, the growth recovery of sorghum under nonuniform salinity stress as well as the inhibited sorghum growth under uniform salinity conditions. The increased expression of salt resistance genes activated in response to the nonuniform salinity distribution implied that the cross-talk between the nonsaline and high-saline sides of the roots exposed to nonuniform salt stress is potentially regulated.


Assuntos
Raízes de Plantas/fisiologia , Estresse Salino , Tolerância ao Sal/genética , Solo/química , Sorghum/fisiologia , Ácido Abscísico/metabolismo , Aquaporinas/metabolismo , Proteínas de Transporte/metabolismo , Produção Agrícola , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/fisiologia , Fotossíntese/efeitos dos fármacos , Fotossíntese/genética , Folhas de Planta/química , Folhas de Planta/metabolismo , Raízes de Plantas/química , Raízes de Plantas/efeitos dos fármacos , Potássio/análise , Potássio/metabolismo , Rizosfera , Salinidade , Sódio/análise , Sódio/metabolismo , Cloreto de Sódio/efeitos adversos
5.
Int J Mol Sci ; 20(20)2019 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-31614661

RESUMO

Aquaporins are a family of transmembrane proteins permeable to water. In mammals, they are subdivided into classical aquaporins that are permeable to water; aquaglyceroporins that are permeable to water, glycerol and urea; peroxiporins that facilitate the diffusion of H2O2 through cell membranes; and so called unorthodox aquaporins. Aquaporins ensure important physiological functions in both exocrine and endocrine pancreas. Indeed, they are involved in pancreatic fluid secretion and insulin secretion. Modification of aquaporin expression and/or subcellular localization may be involved in the pathogenesis of pancreatic insufficiencies, diabetes and pancreatic cancer. Aquaporins may represent useful drug targets for the treatment of pathophysiological conditions affecting pancreatic function, and/or diagnostic/predictive biomarker for pancreatic cancer. This review summarizes the current knowledge related to the involvement of aquaporins in the pancreas physiology and physiopathology.


Assuntos
Aquaporinas/metabolismo , Pâncreas/metabolismo , Pancreatopatias/metabolismo , Humanos , Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Pâncreas Exócrino/metabolismo
6.
Plant Sci ; 287: 110198, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31481193

RESUMO

Aiming to counteract B deficiency impacts, plants have developed different strategies in order to reach an optimal growth in soils with limited B availability. These include B transport mechanisms that involves a facilitated transport, via channel proteins, and a high-affinity active transport driven by borate transporters. The AtNIP5;1 channel protein is a member of Major Intrinsic Protein family which facilitates B influx into the roots under low B supply. In order to explore the phytohormone-dependent regulation of AtNIP5;1, the effects of abscisic acid (ABA), ethylene, auxins and cytokinins on the activity of AtNIP5;1 promoter were evaluated using the reporter line pNIP5;1-GUS. The results show that ABA treatment increased pAtNIP5;1 activity. Besides, a larger B uptake was found following ABA treatment under B deficiency suggesting a role of ABA inducing B uptake. The ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) caused an induction of AtNIP5;1 expression although did not correlate with higher B concentrations nor with an improvement in root growth. On the contrary, auxins and cytokinins caused slight changes in pAtNIP5;1 induction. Altogether, these results show a regulatory role of phytohormones in AtNIP5;1 promoter what may affect B transport. The herein provided information may contribute to better understand the regulation of B transport in plants towards minimizing B deficiency impacts on agriculture.


Assuntos
Aquaporinas/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Boro/metabolismo , Regulação da Expressão Gênica de Plantas , Reguladores de Crescimento de Planta/metabolismo , Ácido Abscísico/metabolismo , Aquaporinas/genética , Arabidopsis/citologia , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Transporte Biológico , Citocininas/metabolismo , Etilenos/metabolismo , Genes Reporter , Ácidos Indolacéticos/metabolismo , Raízes de Plantas/citologia , Raízes de Plantas/genética , Raízes de Plantas/metabolismo
7.
Plant Sci ; 287: 110199, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31481201

RESUMO

Eutrema salsugineum is considered as extremophile model species. To gain insights into the root hydraulic conductivity and the role played by aquaporins in E. salsugineum, we investigated the aquaporin family profiles, plant water status and root hydraulic conductivity under standard (salt-free) and salt stress conditions. We found that there was no variation in the relative electric conductivity of the leaves when the salt concentration was less than 200 mM NaCl, and the transpiration rate dropped to 60.6% at 100 mM NaCl for 14 days compared to that at standard conditions. The pressure chamber techniques indicated that the root hydraulic conductivity of E. salsugineum was repressed by salt stress. However, propionic acid, usually used as an aquaporin inhibitor, unexpectedly enhanced the root hydraulic conductivity of E. salsugineum. The aquaporin family in E. salsugineum was profiled and the PIP aquaporin expression was investigated at the transcriptional and translational levels. Finally, two EsPIPs were identified to play a role in salt stress. The overall study provides evidence on how halophytes maintain their water status and aquaporin regulation pattern under salt stress conditions.


Assuntos
Aquaporinas/metabolismo , Brassicaceae/fisiologia , Regulação da Expressão Gênica de Plantas , Aquaporinas/genética , Transporte Biológico , Brassicaceae/genética , Filogenia , Folhas de Planta/genética , Folhas de Planta/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/fisiologia , Transpiração Vegetal , Estresse Salino , Tolerância ao Sal , Plantas Tolerantes a Sal , Estresse Fisiológico , Água/metabolismo
8.
Oxid Med Cell Longev ; 2019: 2061830, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31379986

RESUMO

Breast cancer is the major cause of tumor-associated mortality in women worldwide, with prognosis depending on the early discovery of the disease and on the type of breast cancer diagnosed. Among many factors, lipids could contribute to breast cancer malignancy by participating in cellular processes. Also, aquaporins are membrane channels found aberrantly expressed in cancer tissues that were correlated with tumor aggressiveness, progression, and metastasis. However, the differences in lipid profile and aquaporin expression between cell types of different malignant potential have never been investigated. Here, we selected three breast cancer cell lines representing the three major breast cancer types (hormone positive, HER2NEU positive, and triple negative) and analyzed their lipid profile and steady state lipid hydroperoxide levels to correlate with cell sensitivity to H2O2. Additionally, the expression profiles of AQP1, AQP3, and AQP5 and the Nrf2 transcription factor were evaluated, before and after oxidative challenge. We found that the lipid profile was dependent on the cell type, with the HER2-positive cells having the lowest level PUFA, whereas the triple negative showed the highest. However, in triple-negative cancer cells, a lower level of the Nrf2 may be responsible for a higher sensitivity to H2O2 challenge. Interestingly, HER2-positive cells showed the highest increase in intracellular ROS after oxidative challenge, concomitant with a significantly higher level of AQP1, AQP3, and AQP5 expression compared to the other cell types, with AQP3 always being the most expressed isoform. The AQP3 gene expression was stimulated by H2O2 treatment in hormone-positive and HER2NEU cells, together with Nrf2 expression, but was downregulated in triple-negative cells that showed instead upregulation of AQP1 and AQP5. The lipid profile and AQP gene expression after oxidative challenge of these particularly aggressive cell types may represent metabolic reprogramming of cancer cells and reflect a role in adaptation to stress and therapy resistance.


Assuntos
Aquaporinas/metabolismo , Ácidos Graxos/análise , Estresse Oxidativo , Aquaporinas/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Cromatografia Gasosa , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Peróxido de Hidrogênio/farmacologia , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptor ErbB-2/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologia
9.
BMC Plant Biol ; 19(1): 345, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31390991

RESUMO

BACKGROUND: Aquaporin (AQP) proteins comprise a group of membrane intrinsic proteins (MIPs) that are responsible for transporting water and other small molecules, which is crucial for plant survival under stress conditions including salt stress. Despite the vital role of AQPs, little is known about them in cucumber (Cucumis sativus L.). RESULTS: In this study, we identified 39 aquaporin-encoding genes in cucumber that were separated by phylogenetic analysis into five sub-families (PIP, TIP, NIP, SIP, and XIP). Their substrate specificity was then assessed based on key amino acid residues such as the aromatic/Arginine (ar/R) selectivity filter, Froger's positions, and specificity-determining positions. The putative cis-regulatory motifs available in the promoter region of each AQP gene were analyzed and results revealed that their promoter regions contain many abiotic related cis-regulatory elements. Furthermore, analysis of previously released RNA-seq data revealed tissue- and treatment-specific expression patterns of cucumber AQP genes (CsAQPs). Three aquaporins (CsTIP1;1, CsPIP2;4, and CsPIP1;2) were the most transcript abundance genes, with CsTIP1;1 showing the highest expression levels among all aquaporins. Subcellular localization analysis in Nicotiana benthamiana epidermal cells revealed the diverse and broad array of sub-cellular localizations of CsAQPs. We then performed RNA-seq to identify the expression pattern of CsAQPs under salt stress and found a general decreased expression level of root CsAQPs. Moreover, qRT-PCR revealed rapid changes in the expression levels of CsAQPs in response to diverse abiotic stresses including salt, polyethylene glycol (PEG)-6000, heat, and chilling stresses. Additionally, transient expression of AQPs in N. benthamiana increased leaf water loss rate, suggesting their potential roles in the regulation of plant water status under stress conditions. CONCLUSIONS: Our results indicated that CsAQPs play important roles in response to salt stress. The genome-wide identification and primary function characterization of cucumber aquaporins provides insight to elucidate the complexity of the AQP gene family and their biological functions in cucumber.


Assuntos
Aquaporinas/fisiologia , Cucumis sativus/genética , Proteínas de Plantas/fisiologia , Aquaporinas/genética , Aquaporinas/metabolismo , Cucumis sativus/metabolismo , Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Peróxido de Hidrogênio/metabolismo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estresse Fisiológico/genética , Transcriptoma , Água/metabolismo
10.
Chem Biol Interact ; 311: 108795, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31419397

RESUMO

Citreoviridin (CIT), a mycotoxin and ATP synthase inhibitor, is regarded as one of aetiology factors of cardiac beriberi and Keshan disease. Thiamine (VB1) and selenium (Se) improve the recovery of these two diseases respectively. The underlying mechanisms of cardiotoxic effect of CIT and cardioprotective effect of VB1 and Se have not been fully elucidated. In this study, we found that ectopic ATP synthase was more sensitive to CIT treatment than mitochondrial ATP synthase in H9c2 cardiomyocytes. CIT inhibited the transcriptional activity of peroxisome proliferator activated receptor gamma (PPAR-γ) in mice hearts and H9c2 cells. PPAR-γ agonist attenuated the inhibitory effect of CIT on mechanistic target of rapamycin complex 2 (mTORC2) and stimulatory effect of CIT on autophagy in cardiomyocytes. CIT induced apoptosis through lysosomal-mitochondrial axis in cardiomyocytes. PPAR-γ agonist and autophagy inhibitor alleviated CIT-induced apoptosis and accelerated cardiac biomarker. VB1 and Se accelerated the basal transcriptional activity of PPAR-γ in mice hearts and H9c2 cells. Furthermore, VB1 and Se reversed the effect of CIT on PPAR-γ, autophagy and apoptosis. Our findings defined PPAR-γ-mTORC2-autophagy pathway as the key link between CIT cardiotoxicity and cardioprotective effect of VB1 and Se. The present study would shed new light on the pathogenesis of cardiomyopathy and the cardioprotective mechanism of micronutrients.


Assuntos
Apoptose/efeitos dos fármacos , Aurovertinas/farmacologia , Autofagia/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Selênio/farmacologia , Tiamina/farmacologia , Animais , Aquaporinas/genética , Aquaporinas/metabolismo , Peso Corporal/efeitos dos fármacos , Linhagem Celular , Masculino , Alvo Mecanístico do Complexo 2 de Rapamicina/genética , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Camundongos , Camundongos Endogâmicos ICR , Miocárdio/metabolismo , Miocárdio/patologia , PPAR gama/agonistas , PPAR gama/genética , PPAR gama/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos , Proteína X Associada a bcl-2/metabolismo
11.
Int J Mol Sci ; 20(16)2019 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-31426275

RESUMO

Plant development and fitness largely depend on the adequate availability of mineral elements in the soil. Most essential nutrients are available and can be membrane transported either as mono or divalent cations or as mono- or divalent anions. Trivalent cations are highly toxic to membranes, and plants have evolved different mechanisms to handle +3 elements in a safe way. The essential functional role of a few metal ions, with the possibility to gain a trivalent state, mainly resides in the ion's redox activity; examples are iron (Fe) and manganese. Among the required nutrients, the only element with +3 as a unique oxidation state is the non-metal, boron. However, plants also can take up non-essential trivalent elements that occur in biologically relevant concentrations in soils. Examples are, among others, aluminum (Al), chromium (Cr), arsenic (As), and antimony (Sb). Plants have evolved different mechanisms to take up and tolerate these potentially toxic elements. This review considers recent studies describing the transporters, and specific and unspecific channels in different cell compartments and tissues, thereby providing a global vision of trivalent element homeostasis in plants.


Assuntos
Cátions/metabolismo , Plantas/metabolismo , Alumínio/metabolismo , Antimônio/metabolismo , Antimônio/toxicidade , Aquaporinas/metabolismo , Arsênico/metabolismo , Arsênico/toxicidade , Cátions/toxicidade , Membrana Celular/metabolismo , Cromo/metabolismo , Cromo/toxicidade , Ferro/metabolismo , Ferro/toxicidade , Oxirredução , Proteínas de Plantas/metabolismo , Vacúolos/metabolismo
12.
Phys Chem Chem Phys ; 21(41): 22711-22721, 2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31454001

RESUMO

Peptide appended pillar[5]arene (PAP) is an artificial water channel resembling biological water channel proteins, which has shown a significant potential for designing bioinspired water purification systems. Given that PAP channels need to be incorporated at a high density in membrane matrices, it is critical to examine the role of channel-channel and channel-membrane interactions in governing the structural and functional characteristics of channels. To resolve the atomic-scale details of these interactions, we have carried out atomistic molecular dynamics (MD) simulations of multiple PAP channels inserted in a lipid or a block-copolymer (BCP) membrane matrix. Classical MD simulations on a sub-microsecond timescale showed clustering of channels only in the lipid membrane, but enhanced sampling MD simulations showed thermodynamically-favorable dimerized states of channels in both lipid and BCP membranes. The dimerized configurations of channels, with an extensive buried surface area, were stabilized via interactions between the aromatic groups in the peptide arms of neighboring channels. The conformational metrics characterizing the orientational and structural changes in channels revealed a higher flexibility in the lipid membrane as opposed to the BCP membrane although hydrogen bonds between the channel and the membrane molecules were not a major contributor to the stability of channels in the BCP membrane. We also found that the channels undergo wetting/dewetting transitions in both lipid and BCP membranes with a marginally higher probability of undergoing a dewetting transition in the BCP membrane. Collectively, these results highlight the role of channel dynamics in governing channel-channel and channel-membrane interfacial interactions, and provide atomic-scale insights needed to design stable and functional biomimetic membranes for efficient separations.


Assuntos
Aquaporinas/química , Calixarenos/química , Membrana Celular/química , Aquaporinas/metabolismo , Biomimética , Membrana Celular/metabolismo , Modelos Moleculares , Conformação Molecular , Simulação de Dinâmica Molecular
13.
Med Hypotheses ; 129: 109249, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31371070

RESUMO

Although once considered by biologists almost exclusively for their toxicity, reactive oxygen (ROS) and nitrogen (RNS) species produced within normal cells under baseline physiological conditions are now appreciated as redox regulators of a wide range of protein functions. Two families of enzymes, the NADPH oxidases (NOXs) and nitric oxide synthases (NOSs), are major sources of ROS/RNS from molecular oxygen. Aquaporins (AQPs) are membrane channels capable of transporting some ROS/RNS, in particular hydrogen peroxide and perhaps nitric oxide. The activities of all these enzymes and channels are sensitive to variations in oxygen levels within the physiological range experienced by cells in the human body. Since ROS/RNS have important physiological roles and their endogenous production is affected by oxygen levels, we hypothesize that the synthesis of these proteins is increased at lower oxygen levels within the physiological range of most human cells in vivo, i.e. 2-5%, in order to facilitate the maintenance of ROS/RNS production rates. We further postulate that this is achieved, at least in part, by transcriptional stimulation mediated by the activity of hypoxia inducible factors (HIFs), which are strongly regulated by oxygen levels over the same range of oxygen. Here we survey the evidence supporting this hypothesis, including induction of expression of NOXs, NOSs, and AQPs at lower oxygen levels, presence of hypoxia response elements in the corresponding human genes, and evidence from chromatin immunoprecipitation (ChIP) experiments that HIF-1 and/or HIF-2 bind these regions. We find a significant amount of empirical data supporting the hypothesis that HIFs could function as physiological regulators of ROS/RNS homeostasis in the normoxic range in human cells.


Assuntos
Fator 1 Induzível por Hipóxia/metabolismo , Óxido Nítrico/metabolismo , Oxigênio/metabolismo , Espécies Reativas de Nitrogênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Aquaporinas/metabolismo , Membrana Celular/metabolismo , Imunoprecipitação da Cromatina , Regulação da Expressão Gênica , Homeostase , Humanos , Hipóxia/metabolismo , NADPH Oxidases/metabolismo , Nitrogênio/metabolismo , Oxirredução
14.
Am J Chin Med ; 47(5): 1133-1147, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31311296

RESUMO

Hyperuricemia is a metabolic disease of the kidney that results in decreased uric acid excretion. Here, we aimed to investigate the effects of ginsenosides and anserine on hyperuricemia and the expression of aquaporin (AQP) 1-4, which are indicators of renal excretion. Ginsenosides and anserine were administered separately or together after the establishment of hyperuricemia with adenine in BALB/c mice. Renal function indexes such as serum uric acid, creatinine, and urea nitrogen were measured in each group of mice, and the expression of AQP1-4 in renal tissues was detected. Serum uric acid and urea nitrogen were decreased in the ginsenoside and the anserine +UA groups. Meanwhile, the uric acid excretion and clearance rate were clearly increased in the co-treatment +UA group (p<0.05). Moreover, ginsenosides or anserine ginsenosides or anserine alone and treatment with both increased the expression of AQP1-4; however, the synergistic effects were more significantly enhanced (p<0.01). We provide the first reported evidence that ginsenosides and anserine have synergistic effects on uric acid excretion. The improvement in renal function in hyperuricemic mice after treatment with ginsenosides and anserine may result from up-regulation of AQP1-4 expressions.


Assuntos
Anserina/administração & dosagem , Aquaporinas/metabolismo , Ginsenosídeos/administração & dosagem , Hiperuricemia/tratamento farmacológico , Animais , Aquaporinas/genética , Nitrogênio da Ureia Sanguínea , Creatinina/sangue , Sinergismo Farmacológico , Quimioterapia Combinada , Humanos , Hiperuricemia/sangue , Hiperuricemia/genética , Hiperuricemia/metabolismo , Rim/efeitos dos fármacos , Rim/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Regulação para Cima/efeitos dos fármacos , Ácido Úrico/sangue
15.
Pan Afr Med J ; 32: 210, 2019.
Artigo em Francês | MEDLINE | ID: mdl-31312322

RESUMO

Disorders of water balance are a disease commonly encountered in our clinical practice. Analysis of vasopressin receptor type II (V2R) is essential to understand the physiology of water balance and it is used as a biological prototype of G protein-coupled receptors (GPCRs). Nephrogenic syndrome of inappropriate antidiuresis (NSIAD) is a syndrome of inappropriate antidiuretic hormone secretion (SIADH) with low plasmatic vasopressin. The evidence on the role of V2 receptor and of aquaporin (AQP) in the mechanism of action for antidiuretic hormone (ADH) was based on the identification of protein gene mutations in patients with nephrogenic diabetes insipidus and NSIAD syndrome. V2R activating mutations were found in patients with NSIAD, contrasting with the numerous V2R inactivating mutations related to X-linked mutations described in patients with nephrogenic diabetes insipidus.


Assuntos
Diabetes Insípido Nefrogênico/fisiopatologia , Doenças Genéticas Ligadas ao Cromossomo X/fisiopatologia , Síndrome de Secreção Inadequada de HAD/fisiopatologia , Receptores de Vasopressinas/genética , Aquaporinas/metabolismo , Diabetes Insípido Nefrogênico/genética , Doenças Genéticas Ligadas ao Cromossomo X/genética , Humanos , Síndrome de Secreção Inadequada de HAD/genética , Mutação , Neurofisinas/metabolismo , Precursores de Proteínas/metabolismo , Receptores de Vasopressinas/metabolismo , Vasopressinas/sangue , Vasopressinas/metabolismo
16.
Am J Bot ; 106(7): 943-957, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31294833

RESUMO

PREMISE: Because of its broad range in the neotropical rainforest and within tree canopies, the tank bromeliad Guzmania monostachia was investigated as a model of how varying leaf hydraulic conductance (Kleaf ) could help plants resist and recover from episodic drought. The two pathways of Kleaf , inside and outside the xylem, were also examined to determine the sites and causes of major hydraulic resistances within the leaf. METHODS: We measured leaf hydraulic conductance for plants in the field and laboratory under wet, dry, and rewetted conditions and applied physiological, anatomical, and gene expression analysis with modeling to investigate changes in Kleaf . RESULTS: After 7 d with no rain in the field or 14 days with no water in the glasshouse, Kleaf decreased by 50% yet increased to hydrated values within 4 d of tank refilling. Staining to detect embolism combined with modeling indicated that changes outside the xylem were of greater importance to Kleaf than were changes inside the xylem and were associated with changes in intercellular air spaces (aerenchyma), aquaporin expression and inhibition, and cuticular conductance. CONCLUSIONS: Low values for all conductances during drying, particularly in pathways outside the xylem, lead to hydraulic resilience for this species and may also contribute to its broad environmental tolerances.


Assuntos
Bromeliaceae/fisiologia , Folhas de Planta/fisiologia , Água/fisiologia , Aquaporinas/metabolismo , Bromeliaceae/anatomia & histologia , Secas , Folhas de Planta/anatomia & histologia
17.
Int J Mol Sci ; 20(13)2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31261636

RESUMO

Protein-ligand docking is a widely used method to generate solutions for the binding of a small molecule with its target in a short amount of time. However, these methods provide identification of physically sound protein-ligand complexes without a complete view of the binding process dynamics, which has been recognized to be a major discriminant in binding affinity and ligand selectivity. In this paper, a novel piece of open-source software to approach this problem is presented, called GPathFinder. It is built as an extension of the modular GaudiMM platform and is able to simulate ligand diffusion pathways at atomistic level. The method has been benchmarked on a set of 20 systems whose ligand-binding routes were studied by other computational tools or suggested from experimental "snapshots". In all of this set, GPathFinder identifies those channels that were already reported in the literature. Interestingly, the low-energy pathways in some cases indicate novel possible binding routes. To show the usefulness of GPathFinder, the analysis of three case systems is reported. We believe that GPathFinder is a software solution with a good balance between accuracy and computational cost, and represents a step forward in extending protein-ligand docking capacities, with implications in several fields such as drug or enzyme design.


Assuntos
Simulação de Acoplamento Molecular/métodos , Software , Algoritmos , Aquaporinas/química , Aquaporinas/metabolismo , Proteínas Arqueais/química , Proteínas Arqueais/metabolismo , Sítios de Ligação , Citocromo P-450 CYP2C19/química , Citocromo P-450 CYP2C19/metabolismo , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/química , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Ligantes , Ligação Proteica
18.
BMC Genomics ; 20(1): 538, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31262248

RESUMO

BACKGROUND: Aquaporins (AQPs) are integral membrane proteins from a larger family of major intrinsic proteins (MIPs) and function in a huge variety of processes such as water transport, plant growth and stress response. The availability of the whole-genome data of different cotton species allows us to study systematic evolution and function of cotton AQPs on a genome-wide level. RESULTS: Here, a total of 53, 58, 113 and 111 AQP genes were identified in G. arboreum, G. raimondii, G. hirsutum and G. barbadense, respectively. A comprehensive analysis of cotton AQPs, involved in exon/intron structure, functional domains, phylogenetic relationships and gene duplications, divided these AQPs into five subfamilies (PIP, NIP, SIP, TIP and XIP). Comparative genome analysis among 30 species from algae to angiosperm as well as common tandem duplication events in 24 well-studied plants further revealed the evolutionary conservation of AQP family in the organism kingdom. Combining transcriptome analysis and Quantitative Real-time PCR (qRT-PCR) verification, most AQPs exhibited tissue-specific expression patterns both in G. raimondii and G. hirsutum. Meanwhile, a bias of time to peak expression of several AQPs was also detected after treating G. davidsonii and G. hirsutum with 200 mM NaCl. It is interesting that both PIP1;4 h/i/j and PIP2;2a/e showed the highly conserved tandem structure, but differentially contributed to tissue development and stress response in different cotton species. CONCLUSIONS: These results demonstrated that cotton AQPs were structural conservation while experienced the functional differentiation during the process of evolution and domestication. This study will further broaden our insights into the evolution and functional elucidation of AQP gene family in cotton.


Assuntos
Aquaporinas/genética , Evolução Molecular , Gossypium/genética , Filogenia , Proteínas de Plantas/genética , Aquaporinas/química , Aquaporinas/metabolismo , Duplicação Gênica , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Estudo de Associação Genômica Ampla , Genômica/métodos , Gossypium/fisiologia , Família Multigênica , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Estresse Salino
19.
Forensic Sci Int ; 301: e44-e48, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31208773

RESUMO

Hanging can be suicidal, accidental, or homicidal, and these backgrounds must be discriminated by police and forensic pathologists. We herein report a case involving a 33-year-old man who was found dead on the floor behind the entrance door of an apartment house. The man's brother declared that he had found him hanging in the gap between the stairs on the top floor. When his brother tried to cut him down, the victim fell three floors down through the gap between the stairs. Autopsy was performed to confirm suicidal hanging and a postmortem fall into the narrow gap. In this case, however, a homicide was suspected, and the version of events told by the victim's brother was initially doubted. Homicidal hanging may be uncommon, but intensive scene investigation and thorough autopsy are necessary in hanging cases to rule out homicide.


Assuntos
Asfixia/patologia , Homicídio , Lesões do Pescoço/patologia , Suicídio , Adulto , Aquaporinas/metabolismo , Epiderme/metabolismo , Medicina Legal/métodos , Fraturas de Cartilagem/patologia , Humanos , Cartilagens Laríngeas/lesões , Cartilagens Laríngeas/patologia , Masculino , Coloração e Rotulagem
20.
Exp Eye Res ; 185: 107682, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31150637

RESUMO

This investigation was undertaken to find out whether the positive charges in the Extracellular Loops A (ELA) and C (ELC) of Aquaporin 0 (AQP0) are involved in lens fiber cell-to-cell adhesion (CTCA), and the possible mechanism of CTCA. AQP0 ELA or ELC was substituted with the corresponding AQP1 loop via Polymerase Chain Reaction. Positively charged arginine (R) and histidine (H) of mouse AQP0 ELA and ELC were substituted individually with glutamine (Q) to create R33Q, H40Q, R113Q and H122Q by mutagenesis. cRNA expression, immunostaining, Förster Resonance Energy Transfer (FRET) studies and protein analyses showed localization of all mutants except AQP0-AQP1ELC chimera (AQP0 ELC substituted with AQP1 ELC) at the plasma membrane. Osmotic Swelling Assay revealed comparable water permeability (Pf) among AQP0-AQP1ELA, R33Q, R113Q, and WT. CTCA assay demonstrated a significant reduction in adhesion in all mutants compared to the WT (14-73%) suggesting the importance of the conserved positively charged residues of ELA and ELC for adhesion. Studies involving AQP0-transfected L-cells, and lipid vesicles indicated that CTCA was due to the electrostatic interaction between the positively charged amino acids of AQP0 extracellular loops and the negative charges of the plasma membrane. Schematic models are provided to illustrate the mechanism.


Assuntos
Aquaporinas/metabolismo , Arginina/metabolismo , Adesão Celular/fisiologia , Membrana Celular/metabolismo , Proteínas do Olho/metabolismo , Histidina/metabolismo , Cristalino/metabolismo , Animais , Western Blotting , Cães , Feminino , Cristalino/química , Células Madin Darby de Rim Canino , Microscopia de Fluorescência , Mutagênese Sítio-Dirigida , Oócitos/metabolismo , Plasmídeos , Reação em Cadeia da Polimerase , RNA/genética , Xenopus laevis
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